GCN Circular 44315
Subject
EP260416a: SVOM/VT optical observation
Event
Date
2026-04-16T14:48:47Z (7 days ago)
From
Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>
Via
Web form
H. L. Li, Y. N. Ma, C. Wu, L. P. Xin, Y. L. Qiu, Z. H. Yao, J. R. Xu, X. H. Han, J. Wang, Y. Xu, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, L. Lan, J. S. Deng, J. Y. Wei (NAOC), J. Palmerio (CEA/Irfu) report on behalf of the SVOM/VT team.
SVOM/VT performed a ToO observation of EP260416a, triggered by Einstein Probe (Hu et al., GCN 44307). The observation started at 2026-04-16T06:17:46 UTC, i.e., approximately 46.8 minutes in the VT_B (400-650 nm) and VT_R (650-1000 nm) channels simultaneously.
The optical candidate reported by COLIBRÍ (Ducoin et al., GCN 44310) was clearly detected in stack images in both channels. The preliminary measurements are given in the AB magnitudes and are not corrected for Galactic extinction:
Mid time | Band | Exposure Time | Brightness
1.93 hr VT_B 99*50 sec 23.36+/-0.25 mag
1.93 hr VT_R 97*50 sec 22.91+/-0.20 mag
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS.